You have several options here.
First, you can use Remote Desktop which comes with Windows Server 2003. This allows you to login remotely and use the machine just as if you were sitting in front of it.
Second, you can enable the Windows Telnet service. Keep in mind that this type of access is inherently insecure as someone can sniff your network traffic and obtain your authentication information.
Third, you can install an SSH Server, such as
SSHWindows or the
Cygwin suite, and ssh to the box. Then you can run the commands, just as in the Telnet server, but it is encrypted.
Last option is to install a VNC server on the Windows machine and use a VNC client to connect to it. This is identical to the Remote Desktop solution, except for the fact that it connects to the console exclusively.
EDIT: To modify the volume settings, I think you will most certainly need to use RDC or VNC.